<!DOCTYPE html>
<html lang="en" ng-app>
<head>
    <meta charset="UTF-8">
    <title>Hello AngularJS</title>
    <script src="//cdn.bootcss.com/angular.js/1.4.3/angular.js"></script>
</head>
<body>
    <!-- Hello {{'World'}}! -->
    Your name: <input type="text" ng-model="yourname" placeholder="World"><hr>
    Hello {{yourname || 'World'}}!
</body>
</html>